Steam-engine.



J. STUMPF. STEAM ENGINE. Arr'LIcATIoH 11mm JULY s4. 1909.

952,764. Patented Mar. 22, 1910.

, J'QHANN s'ruirrrr', otr Bnianrn, Giani/muv.

STEAM-Encina; f

Application led July 24,199. l Serial No. 509,316.

To all whom it may'oncern:

Beit known that T, 'JOHANN STUMPF, a subject of the King of Prussia, and resident of 33 Kurfrstendamm, Berlin, in the Kingdom of Prussia, Germany, professor, have invented new and useful Improvements in Steam-Engines, of which the following is a specification.

This invent-ion relates to steam engines especially locomotive steam engines, in which the inlet is controlled by valves while the exhaust takes place through sepa-rate ports in thc cylinder Walls only used for exhaust. According to the present invention. in order to provide for easy control of the exhaust the exhaust ports lead to a casing in which there is arranged a slide valve, and so that the slide valve may not be lou-ought in cont-act with high pressure and high temperature steam the exhaust ports are arranged to lead from the cylinder at a point midway in the length thereof.

It is already known that piston and other slide valves are not suited for high pressure and high'temperature (superheated) steam, and itY hasbeen Aproposed to employ lift valves for the steam inlet control and pistonJ valves for the exhaust control. Such gears were inipracticable for use in locomotives on accountof the complication introduced by the special eccentrics for the inlet and the exhaust valves. It has also been proposed to overcome the diiiiculty of complication mentioned above by employing four lift valves which were actuatedfrom a single cam rod but this construction is objectionable on account ofthe fact that the exhaust valves require 'a much greater opening. Such an increased 'opening introduces difficulties in the ca se of high speed engines' on account of the increased stroke of the valve and therefore this construction was not well adapted to therequirements of locomotives.

Agle valves while a slide. valve is employed for The objections above mentioned are avoided by employing in combination with i lift valves controlling the steam inlet a sinreciprocating rod for operating all the controlling-the exhaust.

By this construction the valvev gear is very simple as the valves are all arranged in one line as described above with'reference to'the four lift valve arrangement and only a singleslide valve'is required which is specificano-n of Letters raient.

actuated directly. by the.` reqiprocating rod Patented Mar. 22, 1191er.

carrying the cams for the lift valves and is arranged between said lift valves.

i Another advantage of this construction is that the slide valve does not require to be brought into contact with the hot steam. Tf exhaust ports for the steam are provided in the neighborhood of the center of the cylinder only steam which has already expanded somewhat and therefore is reduced 1n -temperature nds its way to the bearing faces of the piston valves. rThus in addition to the combination of a singlev slide valve and a single reciprocating rod the present invention provides means whereby the said slide valve is completely shut oif from contact with steam of high pressure and temperature.

The invention is illustrated in one convenient form in` the accompanying drawing, which shows a vertical sectional elevation through an engine cylinder and valve'box. The inlet valves 'u and o are actuated by a reciprocating cam rod s in the known manner. Between the lift valves Iv 'v' and fixed to move with the reciprocating rod e is the exhaust slide valve a' which is of the piston type and reciprocates within its casing. After passing through the inlet valves o fv the steam passes by way of the ports a ya! to the cylinder. The piston in its motion uncovers exhaust openings o Wherebyfthe steam is ailowed to pass int-o the piston valve casing only after it hasbeen expanded, that is to say only after its temperature and pressure are reduced. The piston valve is also of course protected from the pressure of compression. Thus it will be seen in the figure that if the piston moves from right to left compression will only start after the piston has overrun the port b. Thus owing to the arrangement of the ports b and b at intermediate points in the length of the cylinder the valve m is .protected not only from the high temperature admission steam 4but also from the, compression pressure.

steamengines for high pressure and `high temperature steam,` the combination with the engine cylinder anda reciprocating piston therein, of a valve box having live steam admission' ports. in communication with the cylinder at the ends thereof, and a plurality of exhaust ports arranged at points intermediateV the endsfof the cylinder, reciproeable liftvalvesearranged Within the end portions ofthe valve, box and controlling the passage of steam through said ads AI'nission ports, a reciprocating exhaust .con- `trolling valve also arranged Within the valve box and operating at an angle to the directionof movement of the inlet valves, said exhaust valve comprising means for controlling the exhaust through said several eX- haust ports, a reciprocatingvalve rod connected `to and movable with the exhaust' valve and Ahaving means coperating with i the lift valves to alternately actuate the lat-v ter,` the said exhaust ports being so. located as to be cut out of operation when the piston overruns.

HERMANN RON'IN, GOTTFRIED KERKEN.

have hereunto' set 15 

